1. Technical Field
Aspects of the present invention relates to a belt unit having an endless belt, and an image formation device employing the belt unit.
2. Conventional Art
Conventionally, an image formation device employing the endless belt has been known. In such an image formation device, the endless belt is wound around a pair of rollers. Typically, in such an image formation device, disk-like flange surfaces are provided at axial ends of the rollers in order to prevent the endless belt from moving in the axial direction (hereinafter, such a movement will be referred to as an oblique movement).
In the belt unit for the image formation device, if the endless belt moves obliquely, the image formed on a printing sheet which is fed by the endless belt may be largely deteriorated.
If a force to move the endless belt obliquely is relatively large, the endless belt may climb over the flange surfaces. Aspects of the invention is advantageous in that an improved belt unit which is capable of preventing the obliquely moving endless belt from climbing over the flange surfaces.
According to aspects of the invention, there is provided a belt unit, which is provided with an endless belt, a pair of rollers around which the endless belt is wound, and a regulating member having a flange surface provided at one axial end of at least one of the pair of rollers. The flange surface extends on an outer side with respect to an outer surface of the endless belt wound around the pair of rollers, the flange surface is configured to contact an end, in a width direction, of the endless belt to prevent the endless belt from moving obliquely, and the flange surface is formed with a conical surface which is configured such that a portion closer to a peripheral side of the conical surface is closer to an axial center of the at least one of the pair of rollers.
According to aspects of the invention, there is provided an electrophotographic image formation device, which is provided with an image formation unit forming a developed image formed by developer, and a belt unit. The belt unit is provided with an endless belt, a pair of rollers around which the endless belt is wound, and a regulating member having a flange surface provided at one axial end of at least one of the pair of rollers. The flange surface extends on an outer side with respect to an outer surface of the endless belt wound around the pair of rollers, the flange surface is configured to contact an end, in a width direction, of the endless belt to prevent the endless belt from moving obliquely, and the flange surface is formed with a conical surface which is configured such that a portion closer to a peripheral side of the conical surface is closer to an axial center of the at least one of the pair of rollers.